Our co-pending European patent application No. 08165844.5 filed on 3 Oct. 2008 identifies a need to provide a universal remote control unit able to control a number of different devices such as TV, a VCR, a disc player and an audio system. This co-pending application describes how to store all of the control data necessary to ensure that the functionality of the universal remote control device is not limited, but yet keeps the size of the database small so that the memory required can also be kept small. In this preceding case, a database structure is described in which common control data is stored in virtual remote structures which are available to a number of physical remote structures. The data is hierarchically arranged and inheritance is used to reduce the overall size of the data.
A remote control unit communicates with the electronic device it controls by transmitting signals which carry messages. Generally, infrared (IR) transmissions are used and, in their choice of transmission medium, there is some standardization between various manufacturers. However, although such a message transmitting signal is comprised of a sequence of high level and low level pulses, there is no standardization of the message protocols. Thus, so called universal controllers which are currently available either copy and store the exact messages output from a number of individual remote control units, or provide a lookup table in which those individual messages can be stored. The “universality” of such controllers is limited by the size of the memory in the remote control device.